The present invention relates to an antistatic composition. More particularly, it relates to an antistatic composition for treating paper and other products to be used in photocopy machines and the like. The antistatic composition may also be used in the pre-processing of jumbo, mill, or parent rolls of paper, prior to printing, sheeting, or roll to roll converting. The invention also relates to a method of using the antistatic composition.
Antistatic compositions have been used in various industries. It is known to apply antistatic compositions to paper products for use in photocopy machines, but not with respect to industrial converting processes (ie. application to jumbo, mill or parent rolls of paper prior to processing). However, each of the known compositions and methods of application have drawbacks. The present invention is an improvement over those compositions and methods known in the art.
For example, U.S. Pat. No. 3,615,403 to Cheung teaches a water based electroconductive coating to be applied to the entire surface of paper for use in photocopy machines. The coating includes an N-vinylpyrrolidone polymer, polyvinyl acetate emulsion and an inorganic salt-polyhydric alcohol system. The patent teaches that the application of the composition to paper used in photocopy machines results in improved copy quality.
U.S. Pat. No. 4,370,412 to Cruickshank discloses a water soluble electroconductive material to be applied to paper for use in photocopy machines. The material includes a sulfonated polystyrene and a salt of sulphuric acid and its derivatives. The cation of the salt is selected from ammonium, alkali metals and amines. Application of the electroconductive material improves the retention of ink on the paper, resulting in a better reproduction.
U.S. Pat. Nos. 5,879,748 (to Conti et al) and 5,460,856 (to O""Lenick, Jr.) relate to off-set lithographic printing processes. Each discloses the application of an oil based emulsion to the entire surface of a printed paper substrate.
Conti et al. uses a non-silicone oil aqueous lubricant emulsion including a hydrocarbon oil, a low hydrophillicxe2x80x94lipophilic balanced surfactant, a high hydrophillicxe2x80x94lipophilic balanced surfactant and water. The composition is uniformly applied to the cured heat set printed web. The hydrocarbon oil functions as a lubricant to protect the printed surface.
O""Lenick, Jr. teaches a composition including a mineral oil, dimethylpolysiloxane, a non-ionic emulsification agent and water. The composition is applied to wet ink prior to the curing or heat treatment steps. The mineral oil acts as a lubricant/anti-smudge agent. The dimethylpolysiloxane is an antistatic agent.
The teachings in each of these references has drawbacks, in that the electroconductive compositions are complicated (eg oil in water emulsions). The compositions are not used to reduce static build up between the individual sheets of paper in a bundle, but rather are to improve the quality of the resulting copy. The compositions are applied to the entire surface of the paper, resulting in excess usage for reduction of static build up. The Conti et al. and O""Lenick references are not for ordinary plain paper for use in photocopy machines, but instead are for lithographic processes.
In one aspect of the present invention, there is provided an antistatic composition comprising a hydrocarbon oil for use in treating a substrate for use in processes or machines in which sheets of the substrate are individually fed from a bundle of sheets of the substrate. In a related aspect, the antistatic composition may be used as a treatment in the industrial pre-processing of jumbo, mill, or parent rolls of substrate of any size or grade prior to printing, sheeting, or roll to roll converting.
In another aspect of the invention, there is provided a method of treating a substrate for use in processes or machines in which sheets of the substrate are individually fed from a bundle of sheets of the substrate with an antistatic composition to reduce static between the individual sheets of the substrate, the method comprising applying an antistatic composition including a hydrocarbon oil to at least one lateral margin of the bundle of sheets of the substrate. In a related aspect, the method comprises applying the antistatic composition to at least one end wall of a jumbo, mill or parent roll of substrate prior to printing, sheeting or roll to roll conversion.
The antistatic composition is preferably a single phase composition consisting of or at least essentially consisting of a hydrocarbon oil. The antistatic composition may comprise of up to 100% wt % hydrocarbon oil, and may optionally include one or more additional functional additives. In one particularly preferred aspect, antistatic additives such as a polymeric sulphuric compound, a polyamino polyol, and other known antistatic additives are present in an amount between about 0.001% and 0.10 wt % of the antistatic composition. The composition may optionally include one or more other additives such as antioxidants, stabilizers, corrosion inhibitors, and defoaming agents.
In one preferred aspect, the antistatic composition may be applied to one or more of the edges of the substrate in an amount between about 10 grams and about 50 grams per kilogram of substrate.
The present invention provides a cost effective, hydrocarbon oil based antistatic composition which reduces static in bundles or rolls of substrate to be processed either in an automated or manual fashion. It reduces the occurrence of misfeeds and jams in photocopiers and the like.